help! currency price question

 

belows are close price from MT4 history centre

EURUSD

day 1 1.2072

day 2 1.20483

day 3 1.20892

GBPUSD

day 1 1.39262

day 2 1.39244

day 3 1.39513

EURGBP

day 1 0.8665

day 2 0.86509

day 3 0.86608


however, when I use EURUSD/GBPUSD to find EURGBP, the result is

day 1 0.866855

day 2 0.865265

day 3 0.866529


is my formula incorrect?